Lenin declared the Russian Civil War to be over when his men captured the city of Novocherkassk, capital of the Don region. But this may have been premature. Kornilov and Alexeev‘s army remains at large since it evacuated Rostov. The cossacks of the Kuban region are restive. Across Russia the Bolsheviks‘ enemies are waiting for the right moment to strike against Lenin’s government.
The Bolsheviks have already started to form a Red Army to replace the now disbanded army of the former Tsarist regime. However it is still a ragtag and disorganised body, little more than a workers’ militia and certainly not something that can be expected to fight and win a war against determined enemies. In order to transform the Red Army into an effective fighting force, Trotsky is now appointed as Sovnarkom‘s war commissar, making him effectively both the Red Army’s political director and its commander-in-chief. But although Trotsky is a man of many talents, he has no military experience whatsoever. How is he to remodel the Red Army?
Leon Trotsky in military uniform (Marxists Internet Archive: the Military Writings of Leon Trotsky, Volume 1 (1918))